1. Field of the Invention
The present invention relates to a method and apparatus for processing picture data, in which processed are picture data strings of continuously occurring picture data.
2. Description of the Prior Art
Recently, due to availability of low-priced, high-capacity semiconductor memories and appearance of large capacity storage mediums, such as optical disk, it has become possible to easily deal with a large amount of digital data, especially picture data.
A prior art picture data processing apparatus will be described with reference to the drawings. FIG. 10 is a block diagram showing a prior art picture data processing apparatus, and FIG. 11 is an illustrative diagram showing picture data string inputted to the apparatus shown in FIG. 10. The apparatus in FIG. 10 comprises a temporary memory unit 101, an arithmetic unit 102, a display memory unit 103 for use in conjunction with a display, and a control unit 104. In FIG. 11, each data of the picture data strings 111 is made up of a leading data 112 and a picture data 113.
The apparatus thus arranged operates as follows. The picture data strings illustrated in FIG. 11 are entered into the temporary memory unit 101. It should be noted that due to difference in data structure, the picture data strings stored, for example, in a disk-like storage medium cannot be displayed on an image plane if such picture data are directly sent to the display memory unit 103. It is therefore necessary to convert the picture data to a data having a structure adapted for displaying. In the apparatus in FIG. 10, the data conversion is effected in the arithmetic unit 102, whereupon the resultant data is inputted to the display memory unit 103 and then outputted to the image plane. The arithmetic operation is effected on image plane basis. To this effect, the leading data 112 is used to recognize the picture data 113 for one image plane. Such processings are carried out under control of the control unit 104.
In the prior art picture data processing apparatus, the processings cannot be implemented in the case when one image plane data conversion time is longer than a period of time during which one image plane data is inputted to the temporary memory unit 101. As a rule, the processings cannot be implemented in the case when one unitary picture data conversion time is larger than a period of time during which the unitary picture data is inputted to the temporary memory unit. That is, a problem exists in that the operation cannot be performed in the case where the control unit is incapable of controlling the input of the picture data strings. This may occur when the picture data strings recorded in a compact disk which is generally used for recording and playing back audio information is intended to be sequentially played back.